Improved machine for grinding slate, stone, marble



am am HENRY W. HARPER, OF BERLINSVILLE, PENNSYLVANIA'.

Letters Patent No. 95,343, dated September 28, 1869; antedated March 29, 1869.

-*.f--n-W-f IMPROVED MACHINE FOR G-RINDING- SLATE, STONE, *MARBLE 8cc.

The Schedule referred to in these Letters Patent and making part of the same.

To all whom et may concern Be it known'that I, HENRY W. HARPER, of Berlinsville, Northampton county, Pennsylvania, have invented an Improved Machine for Grinding and Polishing Slatcs and other Materials; and I do hereby declare the following to be a full, clear, and exact description of the same.

My invention consists of a revolving `disk, or its equivalent, to which are secured a number of grinding or polishing, blocks, arranged apart from each other, in combination with a rotating disk or reciprocating bed, for receiving the object to be ground or polished, all being fully described hereafter.

My invention further consists in rendering the said blocks adjustable on the disk, .or its equivalent, in the manner explained hereafter.

The improved machine, although adapted to the reduction and smoothing 'of various materials, is especially applicable to the grinding and polishing of slates.

In order to enable others skilled in the art to make and use my invention, I will now proceed to describe its construction and operation, reference being hadto the accompanying drawing, which forms a part of this specification, and in which- Figure 1 is a vertical section of my improved slategrinding and polishing-machine, and Figure 2,'a plan view of the same.

The frame-work of the machineconsists, in the pres- 'ent instance, of the base A, and two standards, B and B', connected together-by the horizontal beam D, in which, and in suitable steps a a on the base, turn the two vertical shafts, Eand F. 'i To the upper end of the latter shaft is secured the disk G, for holding the slates (l, which are confined bct-ween an inner ring, m, and outer'ring, n, the last of which is permanently secured to the disk, ivhile the inner ring mis split, and can be Vexpanded and contracted at pleasure, by means of bolts .e-e'xp'anded when the slates are admitted to, and released from theirplaces on the disk, and contracted when the slates have to be secured to the same.

Further allusion to this disk, with its rings, will be unnecessary here,as it; forms the subject of an'application for a Apatent heretofore filed; and as itis imma-v terial in the present instance how the' disk or its ap- -pliances may be constructed, providing the plates can beheld on it, andas a reciprocating bed for holding the slates may be used in place of the revolving. disk.

To the upper end of the shaft E is secured a circular plate or disk, H, having a number of radial slots, j, each of which receives the stem tot' a grinder or polisher, j, which issecured to the plate H by a suitable nut, adapted to the screwed 'end of the stem.

These grinders or polishers niay be made of differu ent materials heretofore used lfor the purpose, although I prefer the use of'lordinary vulcanite emery as a material specially well adapted to the purpose.

The two disks may revolve in the same or in contrary directions, but the disk with the grinding-blocks should revolve much faster than that which holds the slates.

\Vhen the grinding or polishing-blocks have to be applied to the slates, the shaft F and its disk Gr are elevated by any suitable appliances -until the surface of the slates come in contact with the blocks, or the shaft E may be so arranged as to be raised and lowered, in which case the disk His depressed until its.k grinding or polishing-blocks are in contact with thev slates.

y The shape of the blocks j is immaterial. They may be round, as shown, or square, or ofothe'r form, but in *y all cases care should :be taken to arrange them at. a distance apart from eachother; for if crowded together they would approachin their action to that of a c'ontinuous grinding or polishing-ring, which is not only more expensive than the blocks,.but inferior A.to the latter, thering'being apt toclog, while 'the blocks ar'-l ranged apart fronr each other clear themselves from the pulver-ized material, and-'are superior to the rings as regards cutting, grinding, and polishing eiiect.

I prefer to make the blocks adjustable from and towardthe centre ofthe disk H, as it may be advisable to alter their relative position. In fact, it would he preferable in many cases for some of the blocks to be nearerto the centre of the disk than others.

p In place of the. disk I-I, a centralheel, with arms, as illustrated by dottedlines in iig. 2, may be used.

I am aware that a revolving disk, carrying a number of revolving grinders or polishers, has been used for operating on'glass. This I do not cla-im, as I consider the securing of the grinders or polishers to the disk essential in carrying out luy-present invention.

It will be evident that although I have heretofore referred to my invention as applied to the grinding and polishing of slates, it is well adapted to the reduction and smoothing of other materials, such as marble or other stone, metals, Sec, I claim as' my invention, andv Letters Patente- V l. Therevolving vdisk H, or its equivalent, to which are secureda mimber oi' grinding or polishing-blocks, arranged-apart from each other, in combination with a rotating disk or reciprocating bed for containing the object to he ground or polished. v

2. Rendering the said blocks adjustable to and from the centre of the disk H, or its equivalent, by means of slots ffin the latter for the reception ofthe stems ofthe blocks, as set forth.

In testimony whereof, I have signed my name to this'spectication, in the presence of two subscribing witnesses.

H. WM. HARPER.

desire to secure by Witnesses:

JOHN M. Howlin, STEPHEN. Krnn'r. 

